The invention relates to a belt deflector on a seat, particularly on a vehicle seat. This belt deflector has a sheet-metal element that is connected with the seat""s sub-structure, which has a belt path surface structured as a saddle.
In motor vehicles that have a seat bench for several persons, side doors that slide, such as buses, and in vehicles without a roof, such as convertibles and beach vehicles, belt deflectors that are attached to the vehicle seat are required to guide safety belts. The belt deflector is supposed to guide the safety belt so that the belt is easy to handle and rests comfortably against the body. The belt deflector must not represent a risk and, in particular, the belt deflector must prevent head injuries during an accident or crash.
The Prior Art
A belt deflector with the characteristics described initially is known from German Patent No. 100 35 148 A1. In this disclosure, lateral elevations are molded onto the belt path region to center the movement of the belt. Furthermore, a stirrup is arranged above the belt path surface, in the ridge region of the saddle, to delimit a belt slot. This stirrup is attached on both faces of the saddle. In case of improper handling, and particularly also in case of a crash, there is the risk that the safety belt will slip off the belt path surface and will jam between the stirrup and the sheet-metal element. Proper function of the belt is then no longer assured. Furthermore, there is the risk that the belt will be damaged.
The invention is based on the task of creating a belt deflector for a vehicle seat which has a simple structural design and assures proper guidance of the belt in cases of improper handling and crash.
Essentially, the saddle has a ridge region that is rounded off in the belt path direction. The saddle also has ears molded onto it in the crosswise direction, on the side, which are formed in sickle shapes as lateral belt path restrictors. This device also has rounded belt guidance surfaces in the belt path direction, whereby the free ends of the sickle-shaped ears extend over at least the border regions of the belt path surface.
The lateral belt path restrictors are molded on, in one piece, in the ridge region of the sheet-metal element. Production takes place via cold-forming methods. The belt path restrictors with a sickle-shaped structure have a domed belt guidance surface that is adapted to the curvature of the ridge region. The belt path restrictors that are structured in sickle shape and perpendicular to the belt path direction extend over at least the border regions of the belt path surface. The distance between the free ends of the sickle-shaped belt path restrictors is preferably smaller than the width of the belt being guided on the belt path surface. In addition, with this design, a separate stirrup for guiding the belt and for delimiting a belt slot is no longer required.
According to a preferred embodiment of the invention, the sheet-metal element has tabs connected at the faces of the saddle for reinforcement, as well as foot elements structured as sheet-metal tabs for attachment to the seat sub-structure. Thus, it is practical if the foot elements are attached at a cross-bar of the seat sub-structure wherein the face tabs of the sheet-metal element are spaced apart from the cross-bar. The foot elements are dimensioned so that they bend out under the stress that occurs during a crash situation, whereby the sheet-metal element drops down until the face tabs make contact with the cross-bar. Because the sheet-metal element drops down under the belt stress that occurs during an accident, the distance between the belt deflector and the head of the seat-belted person increases. As a result, the risk of head injuries is reduced. Furthermore, the deformation of the foot elements has an advantageous effect on the introduction of the hold-back forces into the body of the seat-belted person.
The belt deflector can be attached at any desired point along a cross-bar of the seat sub-structure, specifically as required by the Installation situation in a fixed case. The connection should be made so that the ridge region of the saddle is aligned at a slant to the cross-bar, as determined by the belt path. Preferably, the saddle is structured to be steep on the belt feed side and to have a slide surface with a slant that follows the belt take-off, on the belt take-off side.
In another embodiment, the invention teaches that the foot element on the belt feed side has a shape that has a domed cross-section. This foot element extends as a projecting deflection surface that is perpendicular to the belt path direction. The shape of the foot element forms another deflection surface, which is practical if the safety belt runs upward steeply, following the seat sub-structure.
The sheet-metal element can have an anti-friction coating that reduces the friction resistance. An anti-friction coating made of a fluoride polymer matrix and reinforcement substances embedded in it, with a layer thickness of less than 100 xcexcm, is preferred. While the fluoride polymer matrix of the anti-friction coating imparts sufficient temperature resistance, the embedded, preferably particulate reinforcement substances assure sufficient anti-wear resistance. Because of the low layer thickness of less than 100 xcexcm, preferably 15 to 80 xcexcm, this assures good heat transfer to the metal body, and this in turn has an advantageous effect on the heating of the running surface that occurs in case of a crash. Furthermore, the coating described has a lower noise emission when the belt is pulled out, in comparison with plastic sheathing or chrome-plating.
While the foot elements of the belt deflector are structured so that they bend out under the belt stresses that occur in an accident, the saddle is supposed to possess a high degree of shape stability. The tabs provide an essential reinforcement function wherein they are formed onto the faces of the saddle and connected with one another. It is practical if they are connected by means of rivets.
Both for aesthetic or visual reasons and to avoid the risk of injury, the belt deflector that is attached to the vehicle seat is covered with preferably shock-absorbing material. This results in various design possibilities. One embodiment provides that the foot elements as well as a bottom segment of the saddle are surrounded by an upholstery of the vehicle seat, whereby the ridge region of the sheet-metal element projects out of the upholstery of the vehicle seat. A plastic cap can be set onto the segment that projects out of the upholstery on the belt feed side and belt take off side. The cap has a belt eye for the safety belt to pass through. An alternative embodiment includes a plastic cap that covers the belt feed arranged above the sheet-metal element, whereby the safety belt can be fed in at the bottom of the plastic cap and exits out of a belt opening of the plastic cap, after having been deflected on the saddle of the sheet-metal element. The plastic cap can be integrated into a paneling of the vehicle seat, whereby the feed of the safety belt is also disposed within the seat paneling. Attachment holes for the plastic cap are arranged in the saddle and/or at the faces of the sheet-metal element. According to a preferred embodiment of the invention, the plastic cap attached to the sheet-metal element contains an assembly opening on the saddle side, which can be closed off with a plastic insert.